What are the 2 organisms that are being crossed to make a mule

Donkey and horse are the organisms that are being crossed to make a mule. When a male donkey is breed with female horse, mule is produced. Mule has the characteristics of both horse and donkey. Mule is more in height from donkey and less than horse. It is a very useful animal. Mule is usually found in hilly and mountainous areas for the transportation of goods.